Cerberus KVM: custom 3‑monitor & USB switch control via RS‑232

I built a setup to seamlessly switch input on three monitors and USB devices using RS‑232. Started with a dual‑monitor KVM and a single‑monitor KVM with RS‑232, then hacked apart USB switches and used an Arduino + TTL‑to‑RS‑232 to control them via serial commands.

Chained devices on one RS‑232 bus: dual‑monitor KVM, HDMI switch, USB switch—no interference. Designed a custom controller (3 toggle switches + 4 input buttons + OLED) to select inputs per display and manage USB focus.

Faced challenges: Arduino memory limits in display library (resolved by swapping to a lighter OLED lib), and CNC fitting issues for housing. But after some adjustments, everything fit into a case, soldered and wired cleanly.

Result: reliable daily control—switch HDMI and USB across 3 monitors with a single physical interface.

#WhatsOnMyDesk #desksetup #WeirdDeskThings #WorkFromHome

First post with real info for #WhatsOnMyDesk. I am gonna start with some of the things you can just go buy now!

WASD TKL - They seem to be no more.

DoubleShot Ninja Red KeyCaps https://www.amazon.com/dp/B09SLNZMYM

EX-G PRO Trackball https://elecomusa.com/products/deft-pro-trackball-copy-1

Deco 640 https://www.xp-pen.com/product/deco-640.html

Deskmat is a large hunk of Dakota Brown sugar! https://springfieldleather.com/products/dakota-brown-sugar-5-6-oz-oil-tan

and I always keep some task list notes https://www.jotandmark.com/collections/jot-mark-to-do-lists/products/to-do-list-3-x-5-inches-vertical-index-cards-pack-of-100?variant=18777927301

in my holder
https://www.etsy.com/listing/859030214/task-card-holder

#desksetup #WeirdDeskThings #WorkFromHome

A recent post featuring my cat unexpectedly kicked off some conversations about the more unique or custom accessories on my desk.

So I figured it might be time to start sharing them properly.

I'm starting a little series called #WhatsOnMyDesk, where I'll highlight some of the weirder, more custom, or just plain fun things scattered around my workspace. From retro tech to one-off oddities, I'll try to post something new each week (or whenever I find a moment).

If you're into hardware hacks, cozy workspaces, or just want to see what quietly powers my caffeine-fueled chaos, stick around.

See something you like? Reply and I'll give you a heads-up when I post about it.

#DeskSetup #MastoMakers #HomeLab #WeirdDeskThings #WorkFromHome